PennHip

Dr.Earl Mummert and lead technician Debbie Allen are both certified by the University of Pennsylvania to take PennHip x-rays at Companion Animal Hospital . While OFA x-rays were the popular method to assess dogs for hip dysplasia for 40 years, it is now clear that this screening procedure did relatively little to improve the vast majority of breeds affected by this debilitating problem. It merely helps to identify the arthritis after it has developed. In contrast, PennHip evaluations have significantly reduced joint laxity and the resulting hip dysplasia in breeds such as German Shepherds and Golden Retrievers in less than 10 years. PennHip evaluation can be done as young as 16 weeks of age to assess hip quality before breeding. PennHip is the gold standard for predicting a dog's chances of developing osteoarthritis of the hip joints.

PennHIP (University of Pennsylvania Hip Improvement Program) i s a not-for-profit program, wholly owned and operated, by the University of Pennsylvania . It consists of 3 important components.

• A radiographic procedure to accurately screen a dog's hips for the likelihood of developing hip dysplasia (osteoarthritis).
• A worldwide network of trained veterinarians to perform the procedure with competence.
• A database maintained at the University of Pennsylvania designed to accumulate and report on specific breed trends in OA and hip dysplasia control.

Canine Hip Dysplasia (CHD) affects millions of dogs each year and can result in debilitating osteoarthritis (OA) of the hip. It is estimated that more than 50% of the most popular large breed dogs will show x-ray evidence of CHD . Many will suffer from osteoarthritis, pain, and lameness, costing, owners millions of dollars in veterinary care.

PennHIP's mission is to develop and apply evidence-based technology to direct appropriate breeding strategies aimed at reducing, in frequency and severity, the osteoarthritis of canine hip dysplasia. The beneficiaries of this effort will be the many dogs who suffer with this controllable genetic disease and, of course you, the dogs' owners.

PennHIP incorporates a newer method for evaluating the integrity of the canine hip. It is accurate in puppies as young as 16 weeks of age. It has great potential to lower the frequency of CHD when used as a selection criterion.

What is Canine Hip Dysplasia (CHD)?
A Brief Anatomical Review

The hip is a ball and socket joint. The "ball" is known as the femoral head . The "socket" part of the joint is known as the acetabulum . The femoral head is attached to the inside of the acetabulum by the round ligament and to the periphery of the acetabulum by the joint capsule (see illustration). The joint capsule is a continuous fibrous envelope that surrounds the joint from the neck of the femur to pelvic bones around the acetabulum, this closed compartment is filled with a slippery, lubricating fluid called synovial fluid. Both the joint capsule and the synovial fluid play an important role in the stability of the hip joint and ultimately in the development of CHD .

The muscles that cause rotation of the hip (not shown) are also extremely important for hip stability. Each individual muscle develops a force component that pulls the femoral head into the acetabulum. For proper function and stability of the hip, these forces require complex dynamic coordination and balance.

CHD Definitions

Dysplasia comes from the Greek words dys , meaning "disordered" or "abnormal", and plassein meaning "to form". The expression hip dysplasia can be interpreted as the abnormal or faulty development of the hip. Abnormal development of the hip causes excessive wear of the joint cartilage during weight bearing, eventually leading to the development of arthritis, often called degenerative joint disease (DJD) or osteoarthritis. The terms DJD, arthritis and osteoarthritis are used interchangeably.

CHD was first described in 1937 by Dr. Gerry B. Schnelle. In a paper entitled Bilateral Congenital Subluxation of the Coxofemoral Joints of a Dog Schnelle writes: "The condition described herein, rare though it may be, should be recognized as being congenital and potentially hereditary, and the dog or bitch in which it occurs should be destroyed or sterilized in the eugenic interests of the breed."

In 1966, Henricson, Norberg and Olsson refined the definition of CHD describing it as: "A varying degree of laxity of the hip joint permitting subluxation during early life, giving rise to varying degrees of shallow acetabulum and flattening of the femoral head, finally inevitably leading to osteoarthritis." Today, the general veterinary consensus is that hip dysplasia is hip joint laxity resulting in osteoarthritis.

If you are considering breeding your dog please call CAH for more information on the gold standard for hip evaluation – PennHip x-rays.

P.S. If you or your breeder would like OFA x-rays they can be performed and sent for evaluation at the same time we take the PennHip radiographs. We understand that, while the evidence for using PennHip is strong, some breeders are accustomed to the OFA technique.

For additional information visit www.pennhip.org/PennHIPFAQ.html